1. Field of the Invention
The present invention relates to an improvement in a walking type snow removal machine which is self-propelled by power.
2. Description of the Related Art
In recent years, auger-type snow removal machines which are self-propelled by power and operated by operators walking with the machines have been extensively used to reduce the workload of the operators in clearing snow in a small area. An example of such auger-type snow removal machines is disclosed in, for example, Japanese Patent Laid-Open Publication No. SHO-63-293208 entitled xe2x80x9cPOWER TRANSMISSION DEVICE FOR SNOW REMOVAL MACHINExe2x80x9d.
The disclosed snow removal machine comprises an auger and a blower provided at a front part of the body and handles provided at a rear part of the body. The auger, blower and right and left crawlers are driven by engine power provided via a transmission. The snow removal machine is of a walking type and is relatively small.
However, the snow removal machine is arranged such that snow raked in by the auger is thrown away with the blower through a shoot, thereby limiting a place to clear of snow. For example, there is a limit in using the auger-type snow removal machine in a small area such as a residential area in the suburbs or an urban district. Further, since it employs an engine as a power source, due care should be taken as to noises generated by the engine, especially when the auger-type snow removal machine is used at a quiet time, i.e., in an early morning or at midnight in a residential area or an urban district.
In this context, there has been a demand for a walking-type snow removal machine which can be used easily at any time even in such a small area as a residential area in the suburbs or an urban district.
Further, in the snow removal machine disclosed in the above-mentioned publication, the right and left crawlers always have the same running speed. Accordingly, when the running direction of the snow removal machine is changed or corrected, a difference in rotational speed between the right and left crawlers cannot be absorbed. It is thus required to hold up the snow removal machine with human power to suspend in midair one of the crawlers to change the direction. However, the snow removal machine runs with the crawlers having larger ground-contacting surfaces and has a larger turning radius, thereby presenting a problem of difficult turning.
It is therefore an object of the present invention to provide a walking-type snow removal machine that can be used easily at any time and turns easily with agility.
According to one aspect of the present invention, there is provided a snow removal machine comprising a body frame, a snow removing member provided at the front of the body frame for pushing out snow, operating handles provided at the rear of the body frame, crawler belts provided on the right and left sides of the body frame, an electric motor provided on the body frame for driving the right and left crawler belts through right and left drive wheels, and a battery provided on the body frame for supplying electric power to the electric motor.
The electric motor supplied with power by the battery drives the right and left crawler belts through the right and left drive wheels. The operator controls the operating handles while walking to propel the snow removing machine. The snow removing member provided at the front of the body frame pushes out snow forward to remove snow easily. Thus the snow removal machine can be used even in a small area. Since the electric motor is used as a drive source, the snow removal machine can be made small as compared with a snow removal machine employing an engine. In addition, it generates very small noise and can be used at any time from early morning till midnight.
In a preferred form, the snow removal machine further comprises a control device for controlling the electric motor. The right and left drive wheels are desirably disposed at the front part of the right and left crawler belts. The electric motor is desirably disposed in such a manner that the center of gravity of the electric motor is positioned in the vicinity of the center of axles of the right and left drive wheels. The battery is disposed in such a manner that the center of gravity of the battery is positioned behind the center of gravity of the electric motor. The control device is disposed in such a manner that the center of gravity of the control device is positioned behind the center of gravity of the battery. That is, the electric motor and the battery of relatively large weight are positioned in forward positions, whereby the center of gravity of the snow removal machine is positioned forward, so that the snow removing member easily plunges into snow. Further, since the center of gravity of the snow removal machine is biased to the side of the drive wheels, the driving force of the drive wheels on the crawler belts can be sufficiently obtained. More specifically, the center of the motor shaft of the electric motor may be disposed above and ahead of the center of the axles of the drive wheels. Further, it is preferred to dispose the control device in a position to prevent it from snow damage.
Desirably, an extension line of the body frame is arranged to pass substantially over the center: point of a height of the snow removing member on a snow removing surface of the snow removing member when the body frame is inclined with its front part held downward. In removing snow, snow force acting on the snow removing member in an upwardly slanting direction to the rear is supported on the shaft center of the body frame in the longitudinal direction. Thus, large eccentric load does not act on the body frame.
Preferably, the snow removal machine further comprises a differential gear interposed between the axles on which to couple the right and left drive wheels. Power of the electric motor is transmitted to the right and left drive wheels through the differential gear and the axles. Accordingly, when the running direction of the snow removal machine is changed or corrected, difference in rotational speed between the right and left drive wheels is absorbed by the differential gear. Thus, the snow removal machine can easily change its direction and has a smaller turning radius.